ALT Porphyrin atropisomerism is an outstanding tool for the accessibility of shape-specific molecules. There is a growing need to control this phenomenon in nonplanar porphyrin systems due to the mounting interest in these systems as enzyme mimics and organocatalysts. Hence, in this work, the influence of steric bulk on the stability of nonplanar 5,10,15,20-tetraaryl-2,3,7,8,12,13,17,18-octaethyl-porphyrin atropisomers was explored. The library of atropisomeric porphyrins synthesized herein emphasizes the delicate balance that must be achieved between steric bulk without inducing an undesired amount of macrocycle flexibility to obtain an atropisomer with a predictable rotational barrier. To overcome this challenge, a stabilization strategy was devised by exploiting metal coordination to the peripheral porphyrin functionalities, leading to an atroposelective superstructure formation.

ALT Bicyclo[1.1.1]pentane is a rigid aliphatic hydrocarbon with a three-dimensional (3D), propeller-like shape and a molecular size which makes it a targeted bioisosteric replacement for phenylene and acetylene groups in medicinal chemistry. For the pharmaceutical application of BCP, simple, efficient, and cost-effective synthetic tools are required to enable the exploration of BCP’s potential as a bioisostere across a broad chemical space. The synthesis of BCP mono- and diketones remains a challenging task, limited by both substrate scope and expensive photocatalysts. Here we present a protocol for Friedel-Crafts acylation of (hetero)aromatic hydrocarbons with BCP acyl chlorides; in particular, the first method to access diaromatic BCP 1,3-diketones. Reaction optimization, substrate scope, and reactivity of the products are discussed. 35 mono- and diketones are reported accompanied by 7 examples of post-synthetic modifications. The synthesis of a BCP analogue of fenofibrate is reported.

ALT The growing demand for energy and the excessive use of fossil fuels represents one of the main challenges for humanity. Storing solar energy in the form of chemical bonds to generate solar fuels or value-added chemicals without creating additional environmental burdens is a key requirement for a sustainable future. Here we use biomimetic artificial photosynthesis and present a dPCN-224(H) MOF-based photocatalytic system, which uses reactive oxygen species (ROS) to activate and convert CO2 to ethanol under atmospheric conditions, at room temperature and in 2-5 h reaction time. The system provides a CO2-to-ethanol conversion efficiency (CTE) of 92%. Furthermore, this method also allows the conversion of CO2 through direct air capture (DAC), making it a rapid and versatile method for both dissolved and gaseous CO2.